The objective of the proposal is to identify some of the factors which may be etiologically related to carcinoma of the prostate in the high-risk American black population. About 200 cancer patients and 200 age-matched controls will be included in this study. Specifically, the study will 1) investigate by pretested questionnaires whether dietary and/or lifestyle habits of American blacks are related to the high incidence of prostatic carcinoma, 2) examine the association of carcinoma and morphologic manifestations of aging within the gland in necropsies, 3) explore by atomic absorption spectroscopy the relationship between certain trace metals and carcinoma, in prostate glands removed at autopsy, 4) analyze the vascular patterns in three dimensional reconstructions, in both incidental and invasive carcinoma from necropsy cases, 5) measure by radioimmunoassay free and bound testosterone, dihydrotestosterone, prolactin, estradiol and estrone levels in patients and controls, 6) correlate plasma hormone levels with presence or absence of androgen and estrogen receptors in prostatic tissue and with the clinical response, 7) evaluate the overall capacity of measurement of the counter immunoelectrophoresis (CIEP) method for detection of serum specific acid phosphatase in patients and controls. The clinical features of patients with cancer will be evaluated by established clinical methods and the disease will be staged. Whole prostate glands from necropsy cases will be analyzed for morphologic changes according to a specific protocol. Hormone receptors will be determined by sucrose deniity-gradients ultracentrifugation and protamine precipitation. Significance of all the above data will be determined by appropriate statistical analyses.